A Bidirectional Distance-Balancing Strategy for Connected Automated Vehicles Platoon in Mixed Traffic Flow

Connected and Automated Vehicles (CAVs) are a critical component of modern intelligent transportation systems, offering significant advantages in improving traffic efficiency, enhancing safety, and reducing energy consumption. Among these, CAV platoons have garnered considerable attention due to their ability to maintain stable spatial relationships and reduce time headway through cooperative control. Information Flow Topology (IFT), as a core element of CAV platoon performance, determines the manner in which information is transmitted between vehicles. Although bidirectional IFT demonstrates strong stability advantages in single-vehicle control, its application to CAV platoons faces numerous challenges, and significant research gaps remain. To address this research problem, this paper proposes a bidirectional distance-balancing strategy for CAV platoons, considering sensing and communication delays, which utilizes bidirectional spacing information to maintain vehicles in an equilibrium position between leading and following vehicles. Specifically, a Constant Spacing (CS) strategy is employed to control the following vehicles in the platoon, while a bidirectional information-based distance-balancing strategy is designed for the leading vehicle. Subsequently, numerical simulations are conducted in a mixed traffic flow environment to validate the effectiveness of the proposed strategy in terms of energy consumption, stability, and efficiency. The experimental results demonstrate that the proposed bidirectional distance-balancing strategy for CAV platoons exhibits excellent overall performance. Compared to single-vehicle balancing strategies, energy consumption is reduced by up to 40.81%, and the average travel speed is significantly improved. Compared to platoons without distance balancing, energy consumption is reduced by up to 4.99%, and the propagation of disturbances is better suppressed. This strategy provides a new approach for optimizing CAV platoon formation.